1. Field of the Invention
This invention relates to the magnetic recording art and more paticularly, to improved magnetic recording media comprising a specific type of non-magnetic material in the form of particles in a magnetic recording layer thereof. The term "magnetic recording media" used herein is intended to mean various media including magnetic video or audio tapes, magnetic discs such as floppy discs and hard discs, magnetic cards, and the like.
2. Description of the Prior Art
As is well known in the art, magnetic recording media such as magnetic tapes for use in video tape recorders, floppy discs, and the like comprise oxide powders such as Cr.sub.2 O.sub.3 and/or Al.sub.2 O.sub.3 in the magnetic layer thereof in order to improve the abrasion resistance of the magnetic layer. Moreover, carbon black is added so as to improve antistatic and light-shielding properties of the magnetic layer.
However, these additives must be used in relatively larger amounts in order to attain desired effects thereof. Use of these additives in larger amounts results in a smaller packing density of a magnetic powder in the magnetic layer. Additionally, the magnetic layer becomes so rough on the surface thereof that magnetic characteristics lower. Thus, an improvement of a certain characteristic or property is now attained only with a sacrifice of other desirable characteristics.
From the standpoint of magnetic characteristics such as a recording density, it is desirable to reduce the amount of Al.sub.2 O.sub.3 and/or carbon black. However, this reduction is disadvantageous in improving the antistatic property, light shielding tendency, abrasion resistance and the like. Accordingly, there is a demand for materials which are effective in improving such characteristics as a whole even when used in relatively small amounts.